Upadacitinib Shows Stable Lab Safety in Atopic Dermatitis After 3 Years

What this story is about

If you or someone you care for has moderate to severe atopic dermatitis (often called eczema), you may have heard about a prescription pill called upadacitinib (brand name Rinvoq). New long-term lab data from two major clinical trials suggest the medicine has a stable safety profile when doctors check blood tests over almost three years of treatment.

Quick summary in plain language

Researchers followed people with moderate to severe atopic dermatitis who took upadacitinib for up to 140 weeks. They looked at cholesterol and triglycerides (lipids), liver enzymes, a muscle enzyme called creatine phosphokinase (CPK), and body weight. Most lab results stayed in normal ranges or went back to normal on continued treatment. Serious lab problems were uncommon, and stopping treatment because of a lab issue was rare. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026.)

How the research was done

This report combined two large phase 3 trials called Measure Up 1 and Measure Up 2. These were randomized, placebo-controlled studies that tested upadacitinib 15 mg and 30 mg taken once a day in people aged 12 to 75 with moderate to severe atopic dermatitis. At the start, 603 people were assigned to 15 mg, 610 to 30 mg, and 601 to placebo. At week 16, people on placebo were switched to one of the two doses of upadacitinib. Researchers checked lab tests from the start through week 140. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026.)

Which lab tests were followed

The team looked at:

• Lipids — HDL, LDL, total cholesterol, and triglycerides.
• Liver enzymes — ALT and AST, which help detect liver stress.
• CPK — a muscle enzyme that can rise after exercise or muscle injury.
• Body weight.

What they found

At the start, average lab values were within normal ranges for all groups. Over 140 weeks, most lipid and liver enzyme numbers stayed in normal ranges. When changes did appear, they were usually temporary and often returned to normal without stopping the drug. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026.)

Here are the important details to know:

• Serious elevations (Grade 3 or higher) were uncommon: ALT rose to that level in about 0.6% to 1.3% of patients, AST in about 1.1% to 2.1%, and CPK in about 8.6% to 12.5%.
• Very large liver enzyme spikes (Grade 4) were rare, affecting no more than 0.3% of patients for ALT or AST. Grade 4 CPK events were less than 6%.
• Stopping treatment because of abnormal labs was unusual: 0.7% of patients had stopped by week 52, and fewer than 2% had stopped through week 140.
• An early rise in CPK was seen in the 30 mg group at week 4, with an average of 414.5 U/L. Investigators thought this was largely due to exercise or physical activity. These CPK levels returned to normal for most people, and serious CPK problems were very rare (fewer than 0.1 events per 100 patient-years).

Weight changes

Weight gain was uncommon. In the first 16 weeks, 1.8% of people on 15 mg and 1.9% on 30 mg reported weight increases, compared with 0.6% on placebo. Over the full 140 weeks, the exposure-adjusted event rates for weight gain were low: 1.27 events per 100 patient-years for 15 mg and 1.79 per 100 patient-years for 30 mg. Weight decreases were also rare. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026.)

What this means for people with eczema

The researchers concluded that the pattern of lab tests over nearly three years supports a stable long-term safety profile for upadacitinib in people with moderate to severe atopic dermatitis. Most lab shifts were temporary, and only a small number of people needed to stop the medicine because of lab changes. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026.)

That said, doctors still recommend checking certain blood tests before starting any JAK inhibitor (the drug class that includes upadacitinib) and repeating tests during treatment. These monitoring recommendations are in practical guidance for people with atopic dermatitis taking oral JAK inhibitors. (Source: Kirchhof et al., Dermatol Ther 2024.)

Limitations to keep in mind

This report comes from controlled clinical trials, which help researchers see effects under carefully monitored conditions. Real-world results can differ because people may have other health problems, take other medicines, or be less closely monitored. Talk with your doctor about what monitoring plan makes sense for you.

When to contact your doctor

Call your doctor or dermatologist if you notice any of the following while on treatment:

• New or worsening abdominal pain, yellowing of the skin or eyes (jaundice), or very dark urine.
• Unexplained muscle pain, weakness, or dark-colored urine.
• Sudden, unexplained weight change.
• Signs of infection such as fever, chills, or persistent sore throat.

These could be signs that a lab check or medical evaluation is needed.

Keeping an eye on skin changes

It can help to take photos of your skin over time so you and your doctor can track whether your rash is improving, staying the same, or getting worse. A few clear photos taken every few weeks can make it easier to spot patterns to discuss at appointments.

Disclaimer

This article is for information purposes and does not replace medical advice. Treatment choices and lab monitoring schedules should be discussed with your doctor or dermatologist. If you have serious symptoms or are unsure about anything, seek medical care promptly.

Sources

1. Cotter D, Shahriari M, Dasilva D, et al. Long-term laboratory trends in patients with moderate‑to‑severe atopic dermatitis treated with upadacitinib: 140‑week results from Measure Up 1 and 2. Poster presented at the Society for Investigative Dermatology Annual Meeting, May 13–16, 2026, Chicago, Illinois. (Source: Cotter et al., poster, Society for Investigative Dermatology 2026)
2. Kirchhof MG, Prajapati VH, Gooderham M, et al. Practical recommendations on laboratory monitoring in patients with atopic dermatitis on oral JAK inhibitors. Dermatol Ther (Heidelb). 2024;14(9):2653-2668. doi:10.1007/s13555-024-01243-8. (Source: Kirchhof et al., Dermatol Ther 2024)